FWLF-1631-xx DWDM SFP – June 2009
F i n i s a r
Finisar Corporation Page 8 June 2009 Rev E2
IX. Serial Communication Protocol
All Finisar SFPs support the 2-wire serial communication protocol to provide module ID
information as outlined in the SFP MSA
1
. These SFPs use an Atmel AT24C01A 128 byte
E
2
PROM with an address of A0h. For details on interfacing with the E
2
PROM, see the
Atmel data sheet titled “AT24C01A/02/04/08/16 2-Wire Serial CMOS E
2
PROM.”
7
Finisar SFPs also support diagnostic features as described in Finisar Applications Note
AN-2030
4
and SFF-8472
8
, “Digital Diagnostic Monitoring Interface for Optical
Transceivers”. A controller IC that monitors system parameters such as laser current,
module temperature, transmitter power, and received power is accessible at address A2H.
In addition, Finisar’s DWDM SFPs provide extended set of ID information and diagnostic
features as described in the DWDM SFP MSA
6
.
I2C clock speed, digital diagnostic accuracy and digital diagnostic range can be found in
the table below. Values in the table represent the worst-case values over temperature,
voltage, and life.
Parameter Symbol Min
Typ
Max Units
Notes/Conditions
I
2
C Clock Speed 0 100,000 Hz Bus can be driven blind
Accuracy
Transceiver Case
Temperature
DD
Temperature
-10 +10 °C Measured on the top-side of
the module case
Transceiver Supply
Voltage
DD
Voltage
-3 +3 %
Tx Bias Current DD
Bias
-10 +10 %
Tx Output Power DD
TxPower
-2 +2 dB
Received Average
Power
DD
RxPower
-2 +2 dB
Range
Transceiver Case
Temperature
DD
Temperature
-40 85 °C
Transceiver Supply
Voltage
DD
Voltage
3.0 4.0 V
Tx Bias Current DD
Bias
0 90 mA
Tx Output Power DD
TxPower
-5 +10 dBm
Received Average
Power
DD
RxPower
-30 -7 dBm
